The present invention relates to a novel process for preparing aggregates, and in particular aggregates having a void center and a single cavity in the external surface communicating to the void center referred to as "amphora".
The formation of aggregates by the agglomeration of distinct particles has been accomplished by many methods. The most common technique involves compaction of particles normally together with a binder to form a tablet. Also known is a process in which a slurry comprising a suspending liquid containing distinct particles of a solid is dropped on a particulate bed. See U.S. Pat. No. 3,966,639, the disclosure of which is incorporated herein by reference. As taught in this patent, it is possible to produce aggregates having a void center and a single cavity in the external surface communicating to the void center by suitable control of the operating conditions. Aggregates of this structure, referred to as "amphora," have been found to be ideally suited for use in the manufacture of catalysts for various types of fixed-bed catalytic reactions.